Experimental Results of an Optimized PID Controller for General Anesthesia with Adjustable Opioid-Hypnotic Balance

Closed-loop control of total intravenous anesthesia (TIVA) is an emerging technology expected to have a significant impact on clinical practice in the upcoming years. However, for these systems to become widely acceptable in clinical practice, they should not aim to replace the anesthesiologist; instead, they must act as tools capable of enhancing the abilities of the clinician. Thus, it is important to develop control structures that allow the human operator to adjust the behavior of the controller based on clinical considerations. In the clinical practice of TIVA, balanced anesthesia is a technique that involves properly dosing the administration of propofol and remifentanil to optimize the therapeutic effect of each drug while minimizing their individual side effects. The anesthesiologists perform this technique by regulating the ratio between the infusion rates of these two drugs, known as the opioid-hypnotic balance. In this paper, we present and discuss the experimental results obtained with a PID-based control architecture for propofol and remifentanil co-administration where such a controller has a tuning parameter that can be regulated by the anesthesiologist to achieve the desired opioid-hypnotic balance.